Fixed Jinja chat template for Qwen 3.5, 3.6, and the new 3.8 release

Qwen just released their first 3.8 model. The main addition in 3.8 is prompt-steered reasoning effort. You can tell the model how deeply to think by setting reasoning_effort to xhigh, medium, or low. However, the official template still has some serious problems: You cannot disable thinking. If you

中文全文翻译正在补齐，可先查看下方英文原文。

Qwen just released their first 3.8 model. The main addition in 3.8 is prompt-steered reasoning effort. You can tell the model how deeply to think by setting reasoning_effort to xhigh, medium, or low. However, the official template still has some serious problems: You cannot disable thinking. If you